Published on in Vol 4, No 8 (2020): August
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/13637, first published
.
1 University of California, San Francisco School of Medicine, Stanford, CA, United States
2 Department of Biostatistics and Epidemiology, University of California, San Francisco, San Francisco, CA, United States